1. Field of the Invention
This invention relates generally to improvement in control systems of the type used for operating the heating and cooling apparatus of a building or home and, more particularly, to an improved control system which provides greater control over the heating and cooling a space than has heretofore been possible with conventional equipment.
2. Description of the Prior Art
Many different types of control systems have been used with heating and cooling units of buildings and homes. Control units of conventional designs have been operated under the control of clocks, thermostatic switches, and other moving parts of many different designs. Typical control units are disclosed in U.S. Pat. Nos. 3,964,676, 3,983,928, 4,014,499 and 4,339,073.
Generally, the major drawback of the more preferred conventional control systems of the type described are because they are operated under the influence of a single thermostatic switch throughout an entire 24 hour day. While this type of operation is satisfactory in numerous applications, it is not necessarily efficient in certain situations over an entire day, where, for example, control of the system is not as efficient during the nighttime hours as it is in the daytime hours. Too many shifts in the operating cycle occur for instance, during the nighttime hours when the heating or cooling demand is relatively low. Thus, because of this drawback, a need exists for an improved control system to allow the system to operate in a first mode during one period of a day and in a second mode during another period of the day, so that energy is more efficiently expended in the operation of the heating or cooling apparatus under the influence of the control system.